Study Guide 4

Front 1

Comparative Genomics

Back 1

compares genes in different organisms to see how those organisms are related physiologically

Front 2

Viruses: |s|

Back 2

[5 - 200] kb

Front 3

Bacteria: |s|

Back 3

[1 - 10] Mb

Front 4

Eukaryotes: |s|

Back 4

[10 Mb - 100 Gb]

Front 5

Humans:

Back 5

3 Gb

Front 6

inversions seem to happen around the

Back 6

origin or terminus of replication

Front 7

t/f humans are very unique aniamls

Back 7

Large numbers of genes are in common with
other organisms

Front 8

Strategies for comparative genomics

Back 8

1. phenotyp-centric approach 2. gene-centric approach

Front 9

Phenotype-centric approach

Back 9

Mapping human phenotypes discovered loci to their corresponding mouse phenotype

Front 10

Gene-centric approach

Back 10

Search of orthologs for which a knockout/
expression data is available

Front 11

Chromosomal fusion in the human lineage

Back 11

Humans have 23 pairs of chromosomes and other great apes have 24 pairs of chromosomes. In the human evolutionary lineage, two ancestral ape chromosomes fused at their telomeres producing human chromosome 2

Front 12

There are nine other major chromosomal differences between chimpanzees and humans:

Back 12

chromosome segment inversions on human chromosomes

Front 13

Chimps: no acne, but no asthma, no rheumatoid arthritis

Back 13

true

Front 14

t/f the incidence of cancer in non-human primates is low due to the lack of human cancer genes

Back 14

false; they have human cancer genes, just no cancer

Front 15

example of chiampzee difference in cancer

Back 15

(BRCA1 gene has shown an 8 Kb deletion in the chimpanzee sequence that prematurely truncates the co-regulated NBR2 gene)

Front 16

qtl

Back 16

a genomic region associated with phenotypic variation by linkage to markers

Front 17

Radiometric dating

Back 17

relies on half-life decay of radioactive elements to allow scientists to date rocks and materials directly.

Front 18

Stratigraphy

Back 18

provides a sequence of events from which relative dates can be extrapolated

Front 19

Molecular clocks

Back 19

allow scientists to use the amount of genetic divergence between organisms to extrapolate backwards to estimate dates.

Front 20

What is the old Molecular Clock hypothesis

Back 20

The rate of amino acid replacement in all lineages over evolutionary time is approximately constant

Front 21

Mutations add up at a fairly constant rate in the DNA of species that evolved from a _____

Back 21

common ancestor

Front 22

Different molecules have different mutation rates.higher rate, better for studying ____related species
-lower rate, better for studying ____ related species

Back 22

higher rate, better for studying closely related species
-lower rate, better for studying distantly related species

Front 23

used to study distantly related species

Back 23

Ribosomal RNA

Front 24

t/f a mouse could have multiple mutations over the single lifespan of a human

Back 24

true

Front 25

what is the new molecular clock hypothesis

Back 25

The rate of amino acid replacement is variable
within and between lineages over
evolutionary time

Front 26

Closely related species often share similar properties, likely to have similar rates, give an example:

Back 26

rodents on average 2-6 times faster than apes and humans (GraurLi p150)
-mouse and rat rates are nearly equal

Front 27

Rate Heterogeneity

Back 27

Mutation rates vary among genes and individuals and populations and species

Front 28

three steps to work arount different mutation rates to date divergence

Back 28

Identify lineages that deviate and remove them
2.Quantify degree of rate variation to put limits on possible divergence dates
-requires several calibration dates, not always available
-gives very conservative estimates of molecular dates
3.Explicity model rate variation